Award: OCE-2023349

This central goal of this project was to build upon our understanding of how animals with flexible diets (omnivores) consume different types of prey and why (or when) omnivores shift their diet. We elected to use mysids, a small, shimp-like crustacean that plays a central role in many aquatic food webs as both a consumer and as prey for larger animals. We took a multi-pronged approach to this study, experimentally offering different types of prey at a range of densities and at different water temperatures to two genera of mysid. We then explored mysid diet in the field, using several cutting-edge techniques to unravel what mysids were eating and how their diet changed in response to environmental conditions. This required several experiments to perfect the techniques prior to using them on field-caught specimens. Finally, we evaluated how some of those same conditions affected local mysid abundance, a critical question in many coastal ecosystems that are experiencing large-scale changes.

We found that water temperature had a strong influence on the speed at which mysids consumed different prey, highlighting the importance of temperature as a ‘master’ control of coastal food web processes. We also found that mysids consumed different prey at different rates, indicating that changes in coastal plankton communities could affect higher trophic levels from the ‘bottom up’. Further, we showed that environmental conditions, particularly the availability of oxygen in deep water, can reduce the ability of mysids to feed on near-bottom food webs. This is important because low oxygen (or hypoxic) conditions often form during the summer in deep, coastal areas due to an oversupply of nutrients. Overall, this project has provided us with the tools needed to more accurately include mysids in food webs models, a first-of-its-kind evaluation of mysid stomach contents using genetic metabarcoding techniques, and one of the few studies that has demonstrated direct loss of food web connectedness in response to hypoxia.

This highly collaborative project involved scientists across a broad swath of career stages, including university faculty, professional research technicians, graduate students (PhD and Masters), undergraduate fellows, and community college interns. Overall, three graduate students were partially or fully funded through this project, including two PhD students and one Masters student. Three undergraduate students and three community college interns participated in aspects of the project. We engaged several external collaborators as well over the course of the project, including specialists in stable isotope analysis, and undergraduate educators. Findings from this study were presented in oral and poster format at multiple scientific conferences, while supporting a dedicated symposium at an international conference in Spain (Aquatic Sciences Meeting, 2023). To date, two peer-reviewed manuscripts have been published, one more is in review, and several more will be developed from graduate dissertations and theses.

COVID restrictions early in the project forced us to pivot from K-12 focused outreach activities to community college and undergraduate outreach. Despite this change, we developed novel collaborations that allowed us to work directly with undergraduate students in a Computer Science course. As their final project in the course, the students developed educational tools for teaching the public about coastal food webs. This exposed computer science STEM students to ecological concepts and ideas that were novel to them, while allowing the students to develop computer-based education tools that the science team can use for outreach events.

 

Last Modified: 12/30/2025
Modified by: Ryan J Woodland